Prefabricated stair



July 30, 1963 F. L. HAWKINS 3,099,336

PREFABRICATED STAIR Filed NOV. 14, 1960 2 Sheets-Sheet l INVENTOR. Floyd L. Haw Kins 27 Httarney:

F. L. HAWKINS PEFABRICATED STAIR 2 Sheets-Sheet 2 July 30, 1963 FiledNov. 14. 1960 ,daAA Httorneys United States Patent Ofiice 3,099,336Patented July 30, 1963 3,099,336 PREFABRICATED STAIR Floyd L. Hawkins,Rte. 1, Box 103, Montevallo, Ala. Filed Nov. 14, 1960, Ser. No. 69,094Claims. (Cl. 189-43) This invention relates to a stair and moreparticularly to a stair that comprises a plurality of independentconnected step units.

Heretofore, independent step units have normally been secured to acommon support, such as a stringer. This has required the use ofconsiderable materials and resulted in a relatively heavy structure aswell as being costly since stair constructions have been custom madeheretofore. In some instances, treads and risers have been placed onfixed supports so that the steps and supporting structure could not bedismantled andtransferred to other locations.

The present invention comprises a stair which may be easilyprefabricated and brought to the site of use, and thereafter, it may bedismantled and transferred to another location. It does not employcommon connecting stringers fof the independent step units and onlyrequires the use of a vertical support adjacent the upper step unit orplatform of the stair. 'In some instances, the step units may be secureddirectly to a wall of a building structure without the use of a verticalsupport.

It is the object of the present invention to provide a prefabricatedstair structure comprising a plurality of independent verticallystaggered step units which are secured in overhanging relation to eachother without the use of a common connecting stringer or the likeextending between the separate step units.

A further object of the present invention is to provide a metal staircomprising a plurality of independent step units with each of the stepscomprising a pair of spaced generally parallel channel members with atread member extending between the upper surface of each pair of channelmembers to form a supporting surface, the tread distance betweenadjacent step units being adjustable to varying distances therebyallowing the stair to be adaptable for use under varying conditions. Asingle design of the stair will thereby satisfy several conditions ofuse, so that a special design is not required for each buildingconstruction.

Apparatus embodying features of my invention is shown in theaccompanying drawings, forming a part of this application, in which:

FIG. 1 is a side elevational view of the prefabricated stair comprisingindependent step units and an upper landing supported by verticalsupports;

FIG. 2 is a front elevational view of the stair construction shown inFIG. 1 showing each step comprising a pair of channel members connectedby a tread and riser member;

FIG. 3 is a perspective view of a stringer of one of the step units andhaving a slanted rear end thereon; and,

FIG. 4 is a perspective view of a tread and riser member which forms thesupporting surface on each of the step units and has embossments on theupper surface of the tread to provide a non-slip surface.

Referring now to the drawings for a better understanding of my inventionI show a prefabricated metal stair indicated generally by the numeraland comprising a plurality of independent vertically staggered stepunits '11 leading to a landing 12. Landing 12 may be suitably positionedoutside an entrance to a building or the like (not shown). Verticalsupports 13 are secured to each side of landing 12 by a securing plate14. The lower ends of supports 13 are embedded in concrete indicated bythe letter C. Thus, the only support required for my prefabricated stairis the support for the upper step or landing 12. If desired, and thebuilding is of a construction to support the stair, the stair may befastened to the building without any vertical support.

Each of the step units 11 comprises a pair of stringers 16 in the formof channel members. As shown in FIG. 3, each stringer 16 comprises a web18 with an upper inturned flange 19 and a lower inturned flange 2.1.Flanges 19 and 21 extend in a horizontal direction and have a pluralityof openings 22 extending therethrough. It is understood that membersother than channel memibers could be employed, such as Z-shaped members,or plate and clip members. An inturned clip 20 having openingstherethrough is positioned on the forward end of stringer 16.

A tread and riser member indicated generally by the numeral 23 is shownin FIG. 4 and extends between a a pair of stringers 16. Each tread andriser member comprises a tread 24, an upwardly extending riser 26, and adownwardly extending flange 2.7. Embossments 28 extend upwardly fromtread 24 and form a non-skid surface for the users of stair 10. Openings31 extend through each end of tread 24 so that the tread and risermember 23 may be secured to stringer 16 by suitable securing meansindicated generally by the numeral 32 and comprising a bolt and nutarrangement.

The tread distance D (see FIG. 1) is the distance between the forwardend of stringers 16 of one step unit and the forward end of stringers 16of a superjacent step unit. Tread 24 extends forwardly of the forwardend of stringers 16 to form an overlap or nose distance indicated by theletter N. Distance N is varied when tread distance D is varied. As anexample, as shown in FIG. 1, if distance D is 10" then the overlap ornose distance N is /2 as the overall width of tread 24 is 10 /2. If thedistance D were 8", the overlap N would be 2 /2. Thus, step units 11 maybe adjusted relative to each other to vary tread distance D and therebyvary overlap distance N. This feature allows stair 19 to be adaptablefor different spans.

Stringer 16 for step units 1.1 beneath landing 12 and the uppermost unit11 have slanted rear ends indicated by numeral 35. The lower corner ofrear end 35 is indicated by letter P and is positioned in directvertical alignment with the forward ends 34 of the second superjacentstep for the example above in which the maximum tread distance D of 10"is obtained. For tread distances under 10" the overlap of thesuperjacent steps would be even greater. Thus, the width of twostringers 16 is positioned beneath the width of each of treads 23-.Riser 2 6 may be secured by suitable securing means to clip members 20by suitable securing means 30 (see FIG. 1).

Upper tread member 36 on landing 12 has a rear flange 37 thereon. Flange3-7 may be secured directly to a building or joining structure and insome instances, the use of vertical supports may be elminated.

From the foregoing, it will be understood that I have provided aprefabricated stair comprising independent step units without the use ofa common stringer or support The step units comprise a tread extendingbetween a pair of stringers with each step unit superposed on asubjacent step unit. The independent step units may be movedhorizontally relative to each other so that the tread distance andoverlap or overhang of the tread may be varied. The step units areeasily fabricated and may be erected in a minimum of time and withoutthe use of any complicated tools. Further, the stair is light as thereare no connecting members between each of the step units and since onlya minimum of vertical support is required.

While I have shown my invention in but one form, it

will be obvious to those skilled in the art that it is not so limitedbut is susceptible of various changes and modiflcations withoutdeparting from the spirit thereof, and I desire, therefore, that onlysuch limitations shall be placed thereupon as are specifically set forthin the appended claims.

What I claim is:

1. A stair comprising a plurality of metal independent step units, eachunit comprising a pair of channel shaped stringers spaced from eachother and having horizontally extending flanges thereof contacting andoverhanging horizontally extending flanges of the stringers of asubjacent unit, the overhanging flanges of the stringers having aplurality of vertically aligned openings therein whereby adjacentstringer-s may be adjusted relative to each other to vary the amount ofoverhang between adjacent stringers, and means passing through thealigned openings to secure the units together.

2. In a stair, a plurality of independent generally identical stepunits, each of said units comprising a pair of parallel spaced stringersof equal length, the stringers of each unit being supported on the rearportions of the upper horizontal surfaces of the stringers of asubjacent unit and overhanging said rear portions, a tread memberextending between each pair of stringers on the contacting portionsthereof, there being aligned openings in the stringers whereby the treaddistance of the stair may be adjusted, and means passing through theopenings to secure the units together.

3. A metal stair comprising a plurality of vertically staggered stepunits, each of said step units being substantially identical andcomprising a pair of laterally spaced channel members having inturnedfacing horizontally extending flanges, a rear portion of the flanges oneach channel member overhanging a rear portion of the flanges on thechannel members of a subjacent unit, a tread member extending betweenand secured to the upper flanges of each pair of channel members onnonoverhanging portions thereof, said tread member being mounted foradjustment relative to the channel members, the overhanging flangeportions having a plurality of vertically aligned openings thereinwhereby the tread distance between adjacent step units may be adjusted,and means to support the rear end of the uppermost step unit.

4-. The stair defined in claim 3 in which said tread member comprises ahorizontal section with a flange on each side thereof and embossrnentson the upper surface thereof, the flange on one side extending in adirection opposite the flange on the other side.

5. In a stair, a plurality of vertically staggered independent generallyidentical step units, each of said units comprising a pair of parallelspaced stringers having upper and lower horizontally extending flanges,the stringers of each unit being disposed to contact the rear portionsof the upper flanges of the stringers of a subja-cent unit and tooverhang said upper flanges, a tread member extending between each pairof stringers on the contacting portions of the flanges, and meanssecuring the flanges of contacting adjacent stringers to each other.

References (Iited in the file of this patent UNITED STATES PATENTS2,593,683 Lyons Apr. 22, 1952

1. A STAIR COMPRISING A PLURALITY OF METAL INDEPENDENT STEP UNITS, EACHUNIT COMPRISING A PAIR OF CHANNEL SHAPED STRINGERS SPACED FROM EACHOTHER AND HAVING HORIZONTALLY EXTENDING FLANGES THEREOF CONTACTING ANDOVERHANGING HORIZONTALLY EXTENDING FLANGES OF THE STRINGERS OF ASUBJACENT UNIT, THE OVERHANGING FLANGES OF THE STRINGERS HAVING APLURLAITY OF VERTICALLY ALIGNED OPENINGS THEREIN WHEREBY ADJACENTSTRINGERS MAY BE ADJUSTED RELATIVE TO EACH OTHER TO VARY THE AMOUNT OFOVERHANG BETWEEN ADJACENT STRINGERS, AND MEANS PASSING THROUGH THEALIGNED OPENINGS TO SECURE THE UNITS TOGETHER.